The present invention relates to an optical distance measuring apparatus capable of compensating for measurement error due to electromagnetic induction noise which would lower the accuracy in distance measurement by the optical distance measuring apparatus.
It is known that an optical distance measuring apparatus generally has an error which periodically increases and decreases in accordance with the distance to be measured. Such an error is generally called "measurement error" since it influences the distance measurement. Heretofore, measurement error has been compensated by an electric means.
However, it is difficult to completely eliminate measurement error due to electromagnetic induction noise since the conventinal method for error compensation uses an electric means. Also, the conventional method cannot eliminate the drift in electromagnetic induction noise due to, for example, temperature change when such drift arises after completion of adjustment of the apparatus. In addition, much time is required for the conventional method to carry out highly accurate compensation for the measurement error.